Implant having enhanced initial fixation force

ABSTRACT

The present invention provides an implant having an enhanced initial fixation force, and more particularly, to an implant that may maintain a fixed state without relative movement with respect to vertebral bodies until fusion is completely performed. The implant includes: an implant body inserted between vertebral bodies; and an injection unit installed in the implant body, and configured to inject bone cement into the vertebral bodies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.16/937,887, filed on Jul. 4, 2020, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an implant having an enhanced initialfixation force, and more particularly, to an implant that may maintain afixed state without relative movement with respect to vertebral bodiesuntil fusion is completely performed.

2. Description of the Related Art

A vertebral body includes 32 to 35 vertebrae forming a body, andintervertebral discs, i.e., spinal discs arranged between the vertebrae,and is a portion forming a backbone of a human body that connects anupper skull and a lower pelvis. The vertebrae include 7 cervicalvertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacra, and 3 to5 coccyges from the top. In the case of an adult, 5 sacra are fusedtogether to form one sacral vertebra, and 3 to 5 coccyges are fusedtogether to form one tailbone.

As one of the treatment methods for treating serious spinal diseases fora long time, there is spinal fusion. Such spinal fusion is a surgicalmethod, which includes removing an intervertebral disc, and inserting acage that replaces the intervertebral disc to fuse adjacent vertebralbodies to each other.

When performing the spinal fusion in the lumbar vertebrae, it may bedivided into several techniques: posterior lumbar interbody fusion(PLIF), transforaminal lumbar interbody fusion (TLIF), direct laterallumbar interbody fusion (DLIF), oblique lumbar interbody fusion (OLIF),and anterior lumbar interbody fusion (ALIF) depending on an insertiondirection of the cage.

The PLIF is a method, which includes incising a back along a centerlineof the spine, opening so as to expose all of the vertebral bodies,removing a portion of the posterior side of the vertebra, then removingthe disc, and inserting a PLIF cage between the vertebrae.

The PLIF has been performed from the oldest among the spinal fusions,and is an absolutely necessary method when fusing two or three joints.However, due to a surgical process, the PLIF has various disadvantagessuch as high possibility of adhesion to nerves, ligaments and muscles,extended period of time for healing due to a large incision area, andserious aftereffects for some people.

The PLIF cage is the smallest of the cages used in all spinal fusions,wherein a pair of small cages are displaced on left and right sides ofthe spine.

The TLIF is a surgical method, which includes incising the back in asmall area along both sides of a spinal muscle, exposing the vertebralbodies to a minimum, and then inserting the TLIF cage by replacing thedisc while removing a spinal joint site in a direction coming out of aneuropore. This surgical technique is suitable for a case of one jointdue to advantages of less bleeding, and reduced operation time. However,if an operation over multiple sites is required, the PLIF surgery shouldbe performed. Most of the TLIF cage is formed in an arch shape, suchthat it is placed in the vertebral bodies and rotated so that a convexportion of the TLIF cage faces a stomach. The TLIF cage is larger thanthe PLIF cage, but its support area is smaller than a DLIF cage or ALIFcage which will be described below.

The ALIF has various advantages, such as fast recovery from theoperation and no need to worry about adhesions. However, the ALIF has adisadvantage of requiring highly advanced surgical skill because theoperation is performed by incising an anterior (stomach) to bypassintestines, and approaching the spine. The ALIF cage has an advantage ofhaving the largest support area among all spinal fusion cages.

The DLIF was developed to overcome the disadvantages of the ALIF, PLIF,and TLIF. Since the operation is performed through flank incision, theDLIF has advantages that an interval of stenosed sites between thevertebrae may be more greatly widened than the conventional surgeriesperformed by incision of the back, and there is almost no damage tosurrounding tissues. However, since a psoas muscle and peritoneum arearranged around a route to be operated, there is a problem of causingthigh muscle paralysis if there is a surgical mistake during theoperation. The DLIF cage is smaller than the ALIF cage, but larger thanthe PLIF cage or TLIF cage.

Compared to the DLIF, the safer and more effective method is the OLIF.The OLIF has advantages that the operation route is formed in adirection inclined from the flank, and the operation is possible betweenthe 4th lumbar vertebra (L4) and the 5th lumbar vertebra (L5), which aredifficult to operate by the DLIF due to the psoas muscle and peritoneum.In addition, the possibility of damaging the nerves, which may be aproblem in the DLIF, is significantly less.

In such spinal fusion, the bones may be stably formed only when there isno relative movement between the cage and the vertebrae during the bonesgrowing in or around the cage such that the vertebrae adjacent to upperand lower sides of the cage are fused to each other. If there is arelative movement between the cage and the vertebrae, the bone is notformed, or the upper and lower bones grow, but they are adhered to eachother so as not to be fused.

To solve these problems, the relative movement between the cage and thevertebrae is suppressed by installing additional plates, or installingseparate screws on adjacent vertebrae, respectively, and fixing rods toa coupler of both screws.

However, this method not only requires a separate implant, but also hasa problem of lengthening the operation time due to additional surgery.

PRIOR ART DOCUMENT Patent Document

-   (Patent Document 1) U.S. Pat. No. 9,936,992

SUMMARY OF THE INVENTION

In consideration of the above-mentioned circumstances, it is an objectof the present invention to provide an implant that may maintain a fixedstate without a relative movement with respect to vertebral bodies untilfusion is completely performed.

To achieve the above object, according to an aspect of the presentinvention, there is provided an implant including: an implant bodyinserted between vertebral bodies; and an injection unit installed inthe implant body, and configured to inject bone cement into thevertebral bodies.

The injection unit may include a digger configured to dig into an endplate through rotation.

The digger may be connected to an injection tube having an injectionport, and the digger may have an outlet port configured to discharge thebone cement introduced through the injection port.

The digger may include digger blades formed at both ends thereof to diginto the end plate.

An injection fastening part may be formed around the injection port, andan operation device may be connected to the injection fastening part torotate the digger.

The injection fastening parts may be radially disposed around theinjection port.

The injection fastening parts may be a plurality of protrusions orgrooves longitudinally formed on an outer circumferential surface of anend of the injection tube around the injection port.

The injection unit may include a keel part configured to dig into theend plate in a direction, in which the implant body is inserted.

The implant body may include guide parts formed therein to guide thekeel part, and the keel part may include sliders formed on both sidesthereof, on which the guide parts move.

The keel part may include a plurality of outlet ports formed thereinalong a longitudinal direction thereof, and the outlet ports have across-sectional area decreasing toward a distal part.

The implant body may include a guide block formed on one side thereof toguide the keel part to be introduced.

The injection unit may include an anchor configured to penetrate the endplate in an inclined direction.

The injection unit may include a lifter configured to penetrate the endplate in a vertical direction of the implant body.

A height of the lifter may be increased by an expansion device insertedthrough an operation hole formed in the implant body, and the lifter mayinclude an upper part and a lower part, and the upper part and the lowerpart may include position retaining protrusions formed thereon which areengaged with each other to maintain an increased height thereof.

The injection unit may include a bone screw mounted on a plate attachedto the implant.

The bone screw may include an injection port formed in a head thereofand outlet ports formed in a threaded part thereof to be communicatedwith the injection port.

The plate may be fixed to the implant by a plate fixing screw.

The implant may include bone screw seats formed therein to allow thebone screw to be introduced.

According to the present invention, it is possible to provide an implantcapable of maintaining a fixed state without a relative movement withrespect to vertebral bodies until fusion is completely performed. Inparticular, since the bone cement may cause serious problems such asvascular occlusion when it leaks into the body, the implant of thepresent invention has a structure that may accurately inject the bonecement only into the vertebral body.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating an implant according toEmbodiment 1 of the present invention in a state of inserting into avertebral body;

FIG. 2 is a perspective view illustrating a state, in which a digger ofan injection unit in the implant of Embodiment 1 may rotate to injectbone cement into the vertebral body;

FIG. 3 is a perspective view illustrating the injection unit of theimplant of Embodiment 1;

FIGS. 4 to 6 are perspective views illustrating a variant of Embodiment1;

FIG. 7 is a perspective view illustrating an implant according toEmbodiment 2 of the present invention in a state of inserting into avertebral body;

FIG. 8 is a perspective view illustrating a state, in which a keel partof an injection unit is inserted in the implant of Embodiment 2;

FIG. 9 is a perspective view illustrating the injection unit of theimplant of Embodiment 2;

FIGS. 10 and 11 are perspective views illustrating a variant ofEmbodiment 2;

FIG. 12 is a perspective view illustrating an implant according toEmbodiment 3 of the present invention;

FIG. 13 is a perspective view of an injection unit used in Embodiment 3;

FIG. 14 is a perspective view of a perforation device used in Embodiment3;

FIG. 15 is a perspective view illustrating an implant according toEmbodiment 4 of the present invention;

FIG. 16 is a perspective view of an injection unit of Embodiment 4;

FIG. 17 is a perspective view illustrating an implant according toEmbodiment 5 of the present invention;

FIG. 18 is a perspective view illustrating a state before mounting aplate in the implant of FIG. 17;

FIG. 19 is a perspective view of a bone screw used in FIG. 17;

FIG. 20 is a perspective view illustrating an implant according to avariant of Embodiment 5 of the present invention; and

FIG. 21 is a perspective view illustrating a state before mounting aplate in the implant of FIG. 20.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, preferable embodiments of the present invention will bedescribed with reference to the accompanying drawings. Referring to thedrawings, wherein like reference characters designate like orcorresponding parts throughout the several views. In the embodiments ofthe present invention, a detailed description of publicly knownfunctions and configurations that are judged to be able to make thepurport of the present invention unnecessarily obscure will not bedescribed.

First, an implant 100 according to Embodiment 1 of the present inventionwill be described with reference to FIGS. 1 to 3.

The implant 100 basically includes an implant body inserted betweenvertebral bodies, and an injection unit 130, which is installed in theimplant body and may serve to inject bone cement into the vertebral bodythrough an end plate.

The implant body may be made of a polymer material such as polyetherether ketone (PEEK), which is harmless to a human body, or may be madeof a mixture obtained by combining segments of the polymer material andsegments of a metal material with each other. At this time, the metalmaterial uses metal such as titanium, stainless steel, or the like,which is harmless to the human body. Of course, the entire body may alsobe made of a metal material.

As illustrated in FIG. 1, the implant body includes a distal part 108,which is a region where an insertion thereof into the vertebral bodyside is started, a proximal part 102 disposed on a side opposite to thedistal part 108, and side parts 104 and 106 formed between the proximalpart 102 and the distal part 108. The implant body is formed in asubstantially rectangular shape defined by the proximal part 102, theside parts 104 and 106, and the distal part 108, but it is not limitedthereto, and may include various variants.

A window into which a bone material is inserted may be formed in aregion surrounded by the proximal part 102, the side parts 104 and 106,and the distal part 108. As the bone graft, known materials such asautologous bone or BMP may be used.

The proximal part 102 may include holder seats 118 formed at sidesthereof to be connected with a device for inserting the implant 100. Theholder seat 118 may be formed in various shapes such as a groove, ascrew hole and the like. In addition, bridges 110 and 112 may be formedbetween the pair of side parts 104 and 106 for reinforcing the implant.In particular, in Embodiment 1, a pair of bridges 110 and 112 may bearranged for installation of the injection unit 130, and a diggerreceiving cavity 114, in which a digger 132 of the injection unit 130can be located, may be disposed therebetween.

The injection unit 130 is installed in the digger receiving cavity 114of the implant body. The injection unit 130 of Embodiment 1 ischaracterized by having the digger 132. As illustrated in FIG. 3, theinjection unit 130 includes a digger 132, which has a height equal to orlower than that of the implant 100, and an injection tube 134 integrallyconnected with the digger 132.

The injection tube 134 is rotatably supported by an operation hole 120formed in the proximal part 102 and a through hole 116 formed in thebridge 112.

The injection tube 134 is provided with an injection port 136 formed atone end thereof to allow a bone material to be injected from an outside,and an outlet port 142 formed at the other end thereof to becommunicated with the injection port 136 formed in the digger 132. Inaddition, the injection tube 134 has an injection fastening part 138formed at an end thereof, that is, a portion located in the operationhole 120. The injection fastening part 138 may be fastened with anoperation device (not illustrated) to receive a rotational driving forceof the operation device to rotate the digger 132.

The injection fastening parts 138 may be radially disposed around theinjection port 136. In Embodiment 1, the injection fastening part mayinclude a plurality of protrusions formed on an outer circumferentialsurface of an end of the injection tube 134 to be radially disposedalong the circumference. In this case, a plurality of grooves may beformed other than the plurality of protrusions. Accordingly, theoperation device (not illustrated) may be fastened with the injectionfastening part 138 in a longitudinal direction of the injection tube134. Likewise, when moving the operation device in a direction oppositeto the direction, in which the injection fastening part 138 is coupled,the operation device may be easily separated from the injectionfastening part 138.

The digger 132 is rotated by the rotation of the injection tube 134, andis inserted into the vertebral body by passing through the end plate. Atthis time, outlet port 142 is opened into the vertebral body. Therefore,when injecting the bone cement from the injection port 136, the bonecement, which is injected through the injection port 136 and dischargedfrom the outlet port 142, is filled in the vertebral body, andconsequently, the vertebral body is hardened. As a result, the digger132 may be fixed to the vertebral body.

Consequently, it is possible to immediately expect an initial fixingforce by the bone cement in an initial state, in which the implant 100is inserted into the vertebral body. Therefore, the implant 100 may beseated without a relative movement with respect to the vertebral body,such that bones are formed in and out of the implant 100, and therebyadjacent vertebral bodies may be stably fused.

FIGS. 4 to 6 illustrates an implant 101 according to a variant ofEmbodiment 1. The same parts as those of Embodiment 1 will be denoted bythe same reference numerals and will not be described in detail.

The implant 101 according to the variant is different from the implant100 according to Embodiment 1 in the shape of an injection unit 150.That is, there is no difference in the injection tube 154, the injectionfastening part 158, and the injection port 156 therebetween, but thedigger 152 is different in shape.

The injection unit 130 of Embodiment 1 has a characteristic that thedigger 132 has digger blades 140 formed at both ends thereof in asubstantially round shape with a height increasing toward the outletport 142. On the other hand, the injection unit 150 of the variant has acharacteristic that the digger 152 has digger blades 160 formed at bothends thereof in a sharp shape with a height increasing toward the outletport 162. As a result, the digger 132 of Embodiment 1 may be suitablefor patients with a slightly weaker vertebral body due to osteoporosisand the like, and the digger 152 of the variant may be suitable forpatients with hard bone tissues such as young or male patients.

Next, an implant 200 of Embodiment 2 will be described with reference toFIGS. 7 to 11.

The implant 200 includes an implant body and injection units 230 and 250similar to Embodiment 1. The implant body also includes a proximal part202, side parts 204 and 206, and a distal part 208, and has holder seats218 to be coupled with the device for inserting the implant.

The implant body includes guide parts 210 and 212 formed therein. Theinjection units 230 and 250 are inserted into the guide parts 210 and212. The guide parts 210 and 212 may be formed in a substantially railshape, and as long as they can stably guide the injection units 230 and250, there is no limitation in the shape.

The injection units 230 and 250 include keel parts 232 and 252,respectively. That is, the keel parts 232 and 252 are characterized bydigging into the end plate in a direction, in which the implant body isinserted. The keel parts 232 and 252 are provided with sliders 234 and254 formed on both sides thereof, on which the guide parts 210 and 212may slide.

Each of the keel parts 232 and 252 is provided with a sharp tip portion240 formed at one end thereof to facilitate digging into the vertebralbody.

In addition, the keel parts 232 and 252 may include a plurality ofoutlet ports 238 and 258 formed therein at an interval along thelongitudinal direction thereof. At this time, it is preferable that theoutlet ports 238 and 258 have a cross-sectional area decreasing towardthe distal part so that the bone material may be constantly flown out.The outlet ports 238 and 258 should be arranged in a direction towardthe inside of the vertebral body.

As illustrated in FIGS. 9 and 11, the keel parts 232 and 252 may includedifferent lengths from each other as necessary. However, for stablecoupling, as illustrated in FIG. 8, it is preferable that the length ofthe keel parts 232 and 252 is greater than 50% of the length of theimplant body, or as illustrated in FIG. 10, less than 100% thereof. Inaddition, in order to guide the insertion of the keel parts 232 and 252,a guide block 220 may be further provided in the implant body. Asillustrated in FIG. 7, the guide block 220 is formed in an approximatelyelliptical shape, and has guide ports 222 and 224 formed therein withbeing vertically arranged so that the keel parts 232 and 252 may beguided through the guide ports 222 and 224.

Next, an implant 300 of Embodiment 3 will be described with reference toFIGS. 12 to 14.

The implant 300 includes an implant body and an injection unit 330similar to Embodiment 1. The implant body also includes a proximal part302, side parts 304 and 306, and a distal part 308, and has holder seats318 to be coupled with the device for inserting the implant. Inaddition, a bridge 310 is disposed between the side parts 304 and 306 ina lateral direction.

The injection unit 330 of the implant 300 is characterized by includingan anchor 332 penetrating the end plate in an inclined direction.

The anchor 332 has an injection port 336 and an outlet port 340 formedat both ends thereof, and as illustrated in FIG. 13, is bent upward ordownward as a whole, wherein an anchor tip 338 is formed at one endthereof so as to have a cross-sectional area gradually decreasing towardthe tip to facilitate the penetration into the end plate. In addition,the anchor 332 may have stoppers 334 disposed on the proximal part sideto limit an insertion length of the anchor 332.

In addition, if directly inserting the anchor 332, not only theinsertion itself is difficult but also bone tissue inflows into theoutlet port 340 to prevent the discharge of the bone cement. Therefore,in order to solve this problem, a perforation device 350 as illustratedin FIG. 14 may be used. The perforation device 350 has a shapeapproximately similar to the anchor 332, but is formed as a solid bodywith a smaller cross-sectional area. Further, the perforation device 350has a perforation device tip 352 sharply formed at one end thereof tofacilitate the penetration into the end plate, and a perforation devicegripping part 354 formed at the other end on the side opposite to theperforation device tip 352, which is a seat part that can be grasped bya device for holding the perforation device 350.

Thus, as illustrated in FIG. 12, during an operation, the implant 300 isinserted into the vertebral bodies, the perforation device 350 isinserted into the implant through an operation hole 320 formed in theimplant body to perforate into the end plate, the perforation device 350is removed, and then the injection unit 330 is inserted into the implantbody. Thereafter, the main cement is injected through the injection port336 of the injection unit 330 so that the injection unit 330 can befixed inside the vertebral body.

Then, an implant 400 of Embodiment 4 will be described with reference toFIGS. 15 and 16. The implant 400 includes an implant body and aninjection unit 430 similar to Embodiment 1. The implant body alsoincludes a proximal part 402, side parts 404 and 406, and a distal part408, and has holder seats 418 to be coupled with the device forinserting the implant. In addition, a bridge 410 is disposed between theside parts 404 and 406 in a lateral direction.

The injection unit 430 may include a lifter penetrating the end plate ina vertical direction of the implant body. The lifter has an upper part440 and a lower part 434, wherein one of the upper part 440 and thelower part 434 may be inserted into the other one so as to move relativeto each other. In Embodiment 4, the lower part 434 is configured to beinserted into the upper part 440.

In addition, the lower part 434 and the upper part 440 have a pluralityof position retaining protrusions 436 formed on opposite outer sidesthereof in a lateral direction along the vertical direction of theimplant, respectively. When the lower part 434 and the upper part 440are coupled with each other, it is possible to maintain a position ofthese parts by the position retaining protrusions 436 engaged with eachother.

Further, the lower part 434 includes lower openings 438 formed inopposite sides thereof in a longitudinal direction thereof, and theupper part 440 includes upper openings 442 formed in opposite sidesthereof at positions corresponding to the lower openings 438. Whenassembling, the lower openings 438 and the upper openings 442 maytogether form through holes into which an expansion device (notillustrated) is inserted. In addition, the lower part 434 may include aflange 432 formed at a bottom thereof so as to have the lowest height.

During an operation, the implant 400 is first inserted into thevertebral body, the expansion device (not illustrated) is inserted intoan operation hole 420 formed in the implant body, and then the expansiondevice is operated to push up the lifter with being supported by thelower openings 438 and the upper openings 442. At this time, it ispreferable that the expansion device is inserted through the openingsformed in the lower part 434 and the upper part 440 in the longitudinaldirection to break the end plate, as well as moves the lower part 434and the upper part 440 in a direction away from each other. When thelifter extends by a predetermined height, the lower part 434 and theupper part 440 are maintained in the extended state by the positionretaining protrusions 436, and the bone cement is injected into theinjection unit 430 through the expansion device or other injectiondevices. Accordingly, the bone cement is injected into the vertebralbody through the openings formed in the lower part 434 and the upperpart 440 in the longitudinal direction, thereby securely fixing theinjection unit 430 to the vertebral body.

Next, an implant 500 of Embodiment 5 will be described with reference toFIGS. 17 to 19.

The implant 500 includes an implant body and an injection unit similarto Embodiment 1. The implant body also includes a proximal part 502,side parts 504 and 506, and a distal part 508, and has holder seats 518to be coupled with the device for inserting the implant.

The injection unit includes a bone screw 530 mounted on a plate 520attached to the implant body.

Herein, the implant body is first inserted between the vertebral bodies,and then the plate 520 is fixed to the implant body by screwing a platefixing screw 526 to a mounting hole 512 formed in the implant body. Inthis case, the mounting hole 512 may also be utilized as a devicemounting hole connected to a device for gripping and inserting theimplant body into the vertebral body. The plate 520 includes bone screwreceiving holes 522 and 524 formed in at least one of an upper portionand a lower portion thereof. The bone screw 530 is inserted into thevertebral body through the bone screw receiving holes 522 and 524.

The bone screw 530 has an injection port 536 formed in a head 534thereof and outlet ports 538 formed in a threaded part 532 thereof to becommunicated with the injection port 536. The injection port 536 isintegrally formed in or connected to a hole, into which a driver (notillustrated) is inserted. In addition, it is preferable that the outletport 538 has a cross-sectional area decreasing toward the distal part sothat the bone material may be constantly flown out.

Further, as illustrated in FIGS. 20 and 21, an implant 501 according toa variant of Embodiment 5 may also be considered. The same parts of theimplant 501 as the implant 500 of Embodiment 5 will be denoted by thesame reference numerals.

The implant 501 may be used when the plate 520 has a small lengthbecause an interval between the vertebral bodies is narrow. To this end,the implant 501 may have bone screw seats 514 and 516 formed therein tosecure a space, in which the bone screw 530 can be inserted. The bonescrew seats 514 and 516 may prevent the implant body from interferingwith the bone screw 530 when the bone screw 530 inserted into thevertebral body. In addition, the plate 520 may be fixed to the implantbody without using a separate plate fixing screw, or by using a platefixing screw having a form to cover a portion of the head 534 of thebone screw 530.

While the present invention has been described with reference to thepreferred embodiments and variants, the present invention is not limitedto the above-described specific embodiments and the variants, and itwill be understood by those skilled in the related art that variousmodifications and variations may be made therein without departing fromthe scope of the present invention as defined by the appended claims.

The cage according to the present invention does not require a separateimplant for fixing the vertebral bodies to each other, and it ispossible to expect that the operation time may be reduced to improve theprognosis, and thereby replacing the existing cage.

DESCRIPTION OF REFERENCE NUMERALS

-   -   100, 101, 200, 300, 400, 500, 501: Implant    -   102, 202, 302, 402, 502: Proximal part    -   104, 106, 204, 206, 304, 306, 404, 406, 504, 506: Side part    -   108, 208, 308, 408, 508: Distal part    -   110, 112, 310, 410, 510: Bridge    -   114: Digger receiving cavity    -   116: Through hole    -   118, 218, 318, 418, 518: Holder seat    -   120, 320, 420: Operation hole    -   130, 150, 230, 250, 330: Injection unit    -   132, 152: Digger    -   134, 154: Injection tube    -   136, 156, 236, 256, 336, 536: Injection port    -   138, 158: Injection fastening part    -   140, 160: Digger blade    -   142, 162, 238, 258, 340, 538: Outlet port    -   210, 212: Guide part    -   220: Guide block    -   222, 224: Guide port    -   232, 252: Keel part    -   234, 254: Slider    -   240, 260: Tip portion    -   332: Anchor    -   334: Stopper    -   338: Anchor tip    -   350: Perforation device    -   352: Perforation device tip    -   354: Perforation device gripping part    -   432: Flange    -   434: Lower part    -   436: Position retaining protrusion    -   438: Lower opening    -   440: Upper part    -   442: Upper opening    -   512: Mounting hole    -   514, 516: Bone screw seat    -   520: Plate    -   522, 524: Bone screw receiving hole    -   526: Plate fixing screw    -   530: Bone screw    -   532: Threaded part    -   534: Head    -   536: Injection port    -   538: Outlet port

What is claimed is:
 1. An implant comprising: an implant body insertedbetween vertebral bodies; and an injection unit installed in the implantbody, and configured to inject bone cement into the vertebral bodies. 2.The implant according to claim 1, wherein the injection unit comprises adigger configured to dig into an end plate through rotation.
 3. Theimplant according to claim 2, wherein the digger is connected to aninjection tube having an injection port, and the digger has an outletport configured to discharge the bone cement introduced through theinjection port.
 4. The implant according to claim 2, wherein the diggercomprises digger blades formed at both ends thereof to dig into the endplate.
 5. The implant according to claim 3, wherein an injectionfastening part is formed around the injection port, and an operationdevice is connected to the injection fastening part to rotate thedigger.
 6. The implant according to claim 5, wherein the injectionfastening parts are radially disposed around the injection port.
 7. Theimplant according to claim 6, wherein the injection fastening partsinclude a plurality of protrusions or grooves longitudinally formed onan outer circumferential surface of an end of the injection tube aroundthe injection port.
 8. The implant according to claim 1, wherein theinjection unit comprises an anchor configured to penetrate an end platein an inclined direction.
 9. The implant according to claim 1, whereinthe injection unit comprises a lifter configured to penetrate an endplate in a vertical direction of the implant body.
 10. The implantaccording to claim 9, wherein a height of the lifter is increased by anexpansion device inserted through an operation hole formed in theimplant body, and wherein the lifter comprises an upper part and a lowerpart, and the upper part and the lower part include position retainingprotrusions formed thereon, which are engaged with each other tomaintain an increased height thereof.
 11. The implant according to claim1, wherein the injection unit comprises a bone screw mounted on a plateattached to the implant.
 12. The implant according to claim 11, whereinthe bone screw comprises an injection port formed in a head thereof andoutlet ports formed in a threaded part thereof to be communicated withthe injection port.
 13. The implant according to claim 11, wherein theplate is fixed to the implant by a plate fixing screw.
 14. The implantaccording to claim 11, wherein the implant comprises bone screw seatsformed therein to allow the bone screw to be introduced.